No, Rube, they used to call them powertrain control modules. Then I think they became electronic control modules or engine control modules. Then engine control units. Then came body control modules, which relieved the above multiply named devices of having to control all the gizmos inside the vehicle like power doors and turn signals. Hence the term body control module. It controls essentially all the functions that the PCM ECM ECU does not.

But in the case of an SC2, there was only ever one PCM. And until 1999 it controlled everything as it had for the 7 years before. Make that 8.

99 or 2000 had Saturn budding BCMs in S cars for the first time. Complete with all the past lock II bs.

Yes there were transmission control modules on the automatics come restraint control modules on the airbag systems, ABS control modules on the braking system. But until 99 or 2000, everything in the vehicle, under the hood and in the cabin, was ultimately controlled by some part of the PCM.

Today is vehicles may have two or more ECUs depending on the complexity and design of the system. But the Saturn S car was never in that category. And at the clownish description above of what an ECU feeds to a PCM just makes it more apparent that Troll #7e-34 watches cool YouTube videos and then finds forums to post them in by brand.

In order to be effective in life, to win people over, to convince others of your position, you need to be able to concisely communicate your point.
The first post is exceptionally sloppy with terminology and spends more time insulting me than discussing anything technical.

The second post spends most of its time agreeing with everything I said in response, that's contradicting everything originally stated in the first post, then demonstrates severe misunderstanding of the term tune as used in today's society regarding vehicles.

You can tweak a vehicle's performance in many different ways. But that's not tuning necessarily.

If I have an 04 iron redline, supercharged from the factory, I can put under drive pulleys on it, I can change the cams, I can put headers on it and a 2 1/4-in exhaust for freer flow. And port and polish the heads. Those are all performance mods and will provide, as a group, generally better performance. That is not tuning a car.

The easiest way to tune that particular vehicle is to contact ZZP and give them all the information they ask for about your particular vehicle. They then write a custom firmware, loaded into an ECM, and mail it to you. You plug it in. It starts the car. Many fundamental behaviors are changed. They are changed to match as best they can the performance modifications you have made.

Tuning is also the process of iteratively adjusting things like fuel maps and timing curves with a vehicle on a dyno doing multiple runs to see which configuration produces the best output without overheating and melting down internal parts of the engine. Some of today's ECMs can be dynamically programmed instead of having to reflash the entire firmware.

If you think adjusting the jets on your carb is tuning, then you are right, because there is no master computer system controlling such things.

But you are specifically talking third generation Saturn' s cars, so there really is no point in discussing cars back from the beginning of time, whenever that was. Six of one seven of the other.

For your reference, it's been almost 5 years since I had to ban anyone from this forum for posting like an ignoramus. Please don't break the streak.

Respectfully yours,
Derf"RedBeard"

 

That's a great and detailed explanation of the different "computers" used in our cars nowadays derf. Thanks for that. This old damaged brain can't quite comprehend a couple of the mentioned things, but I understand enough that I'd have to agree with what you said about someone watching youtube videos. And who cares about that streak. I would have pulled the trigger already if I were in your shoes, RedBeard. You can call me GrayBeard!! LMAO

 

look i dont have time to argue at the moment i got you when i get home take some pics for ya neck beard, by the way *whispers* air and fuel mixture is considered part of tuning go back to trade school for mechanics so they can teach you this again. Without proper air n fuel mixture being tuned after adding a turbo or certain modifications you will actually not have the car performing at its peak weather or not youve tuned your pcm, also never claimed to be able to tune your pcm while driving nb.
and lastly i was speaking of tuning by connecting to your ecu via obd 2 and how some ppl instead of taking it to the dyno do it as you drive. which i wouldnt recommend i would just take it to the dyno.

 

I don't get the whole neck beard thing, trizzimac. Would you explain to this old man what that is? I'm sure it's supposed to be an insult, but I have never heard of such a thing. Is that regional where you live? I'm just an old man who thinks if someone's being a wise *** or an azzhole, I'll tell him to his face. I do agree with you that after doing mods to increase hp, that a dyno is the best way for testing.

 

Izz,

Air fuel mix is indeed part of tuning. That's why I mentioned it was.
You mentioned having the ECM feed information to the PCM in your earlier comment, Not connecting through the OBD2 port to the ECU. Your self-contradiction is most troublesome.
You did state above that you and the YouTube dude use some software package and that YouTube dude tunes his car as he drives. Another strike against self-contradiction. Getting kind of annoying at this point.
​​​​​​So you use the software as you stated, yet you recommend a dyno? So why'd you buy the software?

What is the communications mask required to talk to this particular PCM?

I don't believe you've answered a single question I've asked, right down to the year on your SC2. What's with that? If you are doing what you say you are doing, these are simple answers to rattle off.

And clearly you have not done any research on neck beards or you'd know about the many famous people in society over the years that have had neck beards.

You're not one of them

 

So just to try and clarify something in my mind, are you saying you use tuner studios to tune the factory pcm of a saturn s-series? Like op I've been trying to find a program that can program the factory pcm but I've been unsuccessful in doing so

 

Oh I forgot about the guy that called me a neckbeard. That was fun. Ignorance in action.

To my knowledge, there is no software package you can purchase that will tune a Saturn s series car. Not back in the day, not later on, and not now. That's why people fabricated their own turbo systems. Because no one could crack the mask on the PCM.

That being said, I have no idea how you could tune a vehicle while driving it If you cannot communicate with the PCM. Pretty basic reality. Collecting data on which to base a tune that you can never apply is possible, but that's sort of completely pointless.

This whole thing about also tuning your ECU as well as your PCM reeks of ignorance since s cars up until 1999 had only PCMs. Not to mention the fact that early Saturn PCMs were never referred to as ECUs. It wasn't until Saturn started putting body control modules in in 1999 I believe in the third gen s cars that it was then referred to as the ECU because for the first time, it controlled only the engine related functions plus transmission etc.

I don't doubt that there is someone out there more than smart enough to crack that PCM now. The problem being they are thoroughly uninterested and unaware of our plight. Oh, and no one else cares.

​​​​​​ The tuner dude's statement that you could tune pretty much anything since the beginning of computers in cars might have applied before the manufacturers started locking down the PCMs. To my knowledge that statement does not apply to s series Saturns, or I would have blown up both of my SC2s decades ago.

 

Lol alright. I just got my first saturn and I've been using it for racing was looking to try and get a bit more power out of it but seems I'm stuck with suspension tuning only. My class requires you run the factory pcm/ecu (whatever your car has) so stand alone isnt an option for me. Guess I'm stuck with the stock 125 hp. Thanks for your reply I did a lot more research into tuning after reading this thread and I've come to the conclusion that it's just not possible to tune them. I'm brand new to computers only played with carburetors and alcohol injection systems so I don't have near enough skill to crack the code just yet.